People do talk about writing things that "the compiler can understand" so it's nothing new. Also I think you meant to say regular expressions understand strings, not patterns - or that regular expression engines understand patterns.
StopTech
This depends on the definition of understanding. If by understanding you mean mental processing then obviously AI can never do that because it has no mind, it only simulates the behaviors of a mind. But if instead understanding is understood (pun intended) to mean the process of extracting accurate information from something and responding to it in a rational way, then yes AIs do understand lots of things.
Arguably if you give AI access to the nuclear launch system then it can cause human extinction "by itself". Every "by itself" extinction scenario requires some pre-existing circumstances so this has a right to qualify as one of those scenarios.
Contrary to before we now have general purpose AIs that can understand all types of scenarios and make decisions in them. This means they can cause extinction with less human guidance. And there's no strong reason to doubt AI could become as intelligent and autonomous as humans, probably in a decade or two. Then it's pretty much bye bye humans.
But does it have Old Zealand?
Not to mention much more ethical too!
Yeah this sounds awful. Your username is apt for this. Reason #5563 to hate AI.
Maybe next they'll make you prove you're over 18 to buy a computer at the store. Maybe put them behinds safety glass too since they're so dangerous. Or put them on the top shelf where kids can't reach.